View Full Version : Wiring equipment up

loose nut
04-25-2008, 08:30 PM
My old mill/drill was a 220v machine with low amps (5 I think) and was wired with 14 gauge wire, my new mill is a 110v machine that draws 16 amps. I'm guessing that I'll have to rewire to 12 gauge and use a 20 amp breaker. Are there any electrical minded folks here that can say if I'm right or not. This would be under Canadian code. Thanks

04-25-2008, 08:57 PM
You are a long way from Georgia.

THE Old code book here said 12 was good for 20 amps
14ga was good for 15 amps..

Modern wiring insulations are better and can carry more heat.

MOST 120 volt receptacles are not good for 20 amps.. check the box.

04-25-2008, 09:11 PM
Can the new mills motor be rewired for 220? That would make things a lot easier.


04-25-2008, 09:33 PM
from north of the 49th

As far as i know (I am not an electrician) the 12 ga 20 amp bit is fine. There is an abridged version of the Cdn Electrical Code (maybe ON version tho) in local Home Depot stores. You should be able to see the finer points there.

This would get you from the breaker box to the wall outlet. This should be a special plug to announce the 20 amp capacity. From there to the machine could be just a cord - 12 ga - and plug (while the socket is different it will accept the usual 15 amp plug. Make sure that the plug itself is 20 amp or better rated).

Depending on the physical layout, you may prefer armored cable - wired direct into the box, no plug - from the wall to the machine. Never done this myself & don't know if the above book covers it.

Have fun!

loose nut
04-25-2008, 10:19 PM
Most of the mills of this type from other distributors are dual 110/220V but the supplier will only rate this one at 110. The salesman said it might be capable of running on 220 but they will not cover it if something burns up.

I was thinking of hard wiring the cable from the machine into a junction box and doing away with the plug, there isn't any good reason to use one on a permanent installation away (unless it's a code thing).

I checked the AWG rating online for 12 gauge wire and everything I can find says 20amps is OK, BUT I don't trust much off the web.

Mike Burdick
04-25-2008, 10:55 PM
Loose Nut,

If re-wiring is a problem can you put the "old" mill drill's motor on the new one...or buy a good 220V motor?

How about a 3 phase motor and a VFD?:)

04-25-2008, 11:59 PM
Yes, you are correct. Canadian electrical code wants #12 with 20 amp breaker. At 16 amps full load you might want to wire in a 20 amp single pole/single throw switch nearby for maintenance/convienence.

04-26-2008, 12:00 AM
Loose Nut,

I can only speak for the code in the US so check with a local electrician or code book. In the US 14 Ga for 15 amp, 12 Ga for 20 amp, 10 Ga for 30 amp. Also, like Dave said above most outlets are only rated for 15 amp BUT they allow you to use them on a 20 amp circuit. That is not a problem in most applications, however if you are going to use the outlet on a heavy load (like the mill) you really should buy an outlet rated for 20 amps. I would also recommend an industrial outlet, They cost less than $5.00US and are worth every penny for heavy duty applications. As for wiring the mill permanently that is an OK idea, however in the US you MUST provide a "Disconnecting Means" for the machine. This can be a disconnect switch on the wall OR a cord that can be unplugged from the outlet. Hmmmm, cord is cheaper :D .
Whatever you do just do it safely ;)

Good luck,

04-26-2008, 12:52 AM
I'm still stuck on your salesmans answer- a stupid one. It seems from his comment that he doesn't know if the motor is capable of being wired for 220. It might be, in which case there should be no reason why you couldn't do it and remain in warranty. A look in the connection box on the motor wil tell the tale. If it is a 110 only motor, the salesman should not have been vague about it, he should have been able to tell you definitively that either you can't run it on 220, or that it can be rewired for 220, even if it has been supplied wired for 110. If it's 110 only, and you run it on 220, that definitely voids the warranty, that should have been made clear.

04-26-2008, 07:35 AM
If it burns up on 220, you rewired it to 110 before you return it.

Simple and easy.

04-26-2008, 08:26 AM
For just a few dollars more 10ga and a 30amp would be my pick.That way if you want to add something to the mill later like a powerfeed,coolant pump or DRO you have the needed capacityalready there.

04-26-2008, 08:44 AM
If it burns up on 220, you rewired it to 110 before you return it.

Simple and easy.

Now snowman you seem to think like me. Besides look at the plate on the motor. And it should tell you everything you want to know.

04-26-2008, 08:48 AM
12 gauge it is. 14 gauge is only allowed to a maximum of 12.5 amps continuous duty. If you use 10 gauge you need to make sure the receptacle is rated to handle that size of wire and that the box has enough room. 10 gauge is pretty stiff wire and having enough room makes it a lot easier to deal with.

Oh BTW, you can buy a Federal 30 amp knife switch box with dual fuses at Canadian Tire for $30. That's what I use for my RPC and for the shaper on/off.

04-26-2008, 02:25 PM
You might find that you have a standard dual voltage motor. Some companies wire 110 volt because they can legally use a SPST switch, which is a bit cheaper than either a DPST or a contactor. Wire it 220 volt with the proper switch and you will be much happier. Evan is correct. I think the brand is Wiremold; it is a type of strip wiring with relocatable single outlets that is often used in laboratories. It is always wired 12 ga with a 20A cct breaker.

J Tiers
04-26-2008, 02:37 PM
What wire is "good for" and what it is "allowed" are two different things.

12 ga is "good for" 30A, but in US NEC (and presumably Canada) it is limited to a 20A breaker AND a 16 amp long term load.

The 16A long term load is not about the wire, but actually about the "molded case" breaker, which is limited to 80% of nominal rating, long term. One can argue very easily that a machine tool is not a "long term load" the way a ventilating fan, or electric heater would be.

I concur with the utter worthlessness of the salesperson. Look at the motor nameplate to see if it can be wired for "220" . Or post a picture of it and we'll decode it for you.

Typically the actual motor wiring diagram is either ON the nameplate, or on the inside surface of the motor wiring box cover.

I suppose it is also possible that any lamps or pilot lights, starter coils, switches etc might have voltage limits also. If any of those items are present, you will have to tell us about them, cuz we aren't looking at the unit.

loose nut
04-26-2008, 03:51 PM
OK, I went out to look at the name plate on the motor just to double check it, and it is rated for 110V 16 Amps, there is nothing on it to say it is dual rated. I also took to cover plate off the motor and there isn't a wiring diagram that would indicate that it can be wired in any way other than 110V.

I don't think the salesman did anything wrong, he was just covering his own butt by saying what was on the motor. If he said anything otherwise he could probably be held accountable if there is a problem.

I' m going to bite the bullet and wire it for 110V, that is the safe way. I have some Scots blood in me and I don't like the idea of having to go out and buy 50" of new wire and a new breaker.

I believe that the US and Canadian elec. codes are basically the same, we use the same basic system and most of the grid is integrated between the two countries so they must (should but who knows) work the same way.